Porous membranes

Abstract

The present invention relates to a porous membrane, process for the manufacture thereof and uses thereof.

The invention claimed is: 
     
       1. A porous membrane comprising at least one layer obtained from a composition (C), said composition (C) comprising:
 at least one F-TPU polymer, which is a fluorinated polyurethane polymer comprising recurring units derived from: 
 optionally, at least one polymer (a), wherein polymer (a) is a diol selected from the group consisting of poly-ether diols, poly-ester diols, polybutadiene-diols and polycarbonate-diols; 
 at least one polymer (b), wherein polymer (b) is a hydroxy-terminated (per)fluoropolyether polymer with a (per)fluoropolyoxy alkylene chain [chain (R pf )] having two chain ends, wherein both chain ends terminate with at least one —OH and chain R pf  is a chain of formula HO-D-(CFX # ) z1 —O(R f )(CFX*) z2 -D*-OH, wherein
 z1 and z2, equal or different from each other, are equal to or higher than 1; X #  and X*, equal or different from each other, are —F or —CF 3 , provided that when z1 and/or z2 are higher than 1, X #  and X* are —F; 
 D and D*, equal or different from each other, are an alkylene chain comprising from 1 to 6 carbon atoms, said alkylene chain being optionally substituted with at least one perfluoroalkyl group comprising from 1 to 3 carbon atoms; and 
 (R f ) comprises repeating units R o , said repeating units being independently selected from the group consisting of:
 (i) —CFXO—, wherein X is F or CF 3 ; 
 (ii) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF 3 , with a proviso that at least one of X is —F; 
 (iii) —CF 2 CF 2 CW 2 O—, wherein each W, equal or different from each other, are F, Cl, or H; 
 (iv) —CF 2 CF 2 CF 2 CF 2 O—; 
 (v) —(CF 2 ) j —CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O—R (f-a) -T, wherein R (f-a)  is a fluoropolyoxyalkene chain comprising a number of repeating units from 0 to 10, said repeating units being chosen among the following: —CFXO—, —CF 2 CFXO—, —CF 2 CF 2 CF 2 O—, or —CF 2 CF 2 CF 2 CF 2 O—, with each of X being independently F or CF 3  and T being a C 1 -C 3  perfluoroalkyl group; 
 
 
 at least one monomer (c), wherein monomer (c) is an aromatic, aliphatic or cycloaliphatic diisocyanate; and 
 at least one monomer (d), wherein monomer (d) is an aliphatic, cycloaliphatic or aromatic diol having from 1 to 14 carbon atoms; and 
 optionally at least one further ingredient. 
 
     
     
       2. The porous membrane according to  claim 1 , wherein said membrane has an average pore diameter of at least 0.001 μm and of at most 50 μm. 
     
     
       3. The porous membrane according to  claim 1 , wherein said optional at least one polymer (a) is selected from the group consisting of poly (ethylene glycol), poly (propylene) glycol, poly (tetramethylene) glycol (PTMG), poly (1,4-butanediol) adipate, poly (ethanediol-1,4-butanediol) adipate, poly (1,6-hexandiol-neopentyl) glycol adipate, poly-caprolactone-diol (PCL) and polycarbonate-diol. 
     
     
       4. The porous membrane according to  claim 1 , wherein said at least one monomer (c) is selected from the group consisting of 4,4′-methylene-diphenylene-diisocyanate (MDI), 1,6-hexane-diisocyanate (HDI), 2,4-toluene-diisocyanate, 2,6-toluene-diisocyanate, xylilen-diisocyanate, naphthalene-diisocyanate, paraphenylen-diisocyanate, hexamaethylene-diisocyanate, isophorone-diisocyanate, 4,4′ dicyclohexyl-methane-diisocyanate and cyclohexyl-1,4-diisocyanate. 
     
     
       5. The porous membrane according to  claim 1 , wherein said at least one monomer (d) is selected from the group consisting of ethylene-glycol, 1,4-butanediol (BDO), 1,6-hexane diol (HDO), N, N-diethanolamine and N, N-diisopropanolaniline. 
     
     
       6. A process for manufacturing the porous membrane according to  claim 1 , said process comprising:
 processing a composition (C) thereby providing a film, 
 and processing the film thereby providing a porous membrane. 
 
     
     
       7. A method for filtering a liquid and/or gas phase comprising one or more solid contaminants, said method comprising contacting said liquid phase and/or gas phase comprising one or more solid contaminants with at least one porous membrane as defined in  claim 1 . 
     
     
       8. The method according to  claim 7 , wherein said solid contaminants are microorganisms selected from the group consisting of bacteria, algae, fungi, protozoa and viruses. 
     
     
       9. The method according to  claim 7 , wherein said porous membrane has an average pore diameter of at least 0.001 μm and of at most 5 μm. 
     
     
       10. The method according to  claim 7 , wherein said porous membrane has an average pore diameter of at least 5 μm and of at most 50 μm. 
     
     
       11. A fabric comprising at least two layers, wherein at least one layer comprises a porous membrane as defined in  claim 1 . 
     
     
       12. The fabric according to  claim 11 , wherein said porous membrane has an average pore diameter of at least 0.001 μm and of at most 5 μm.